Historians and chroniclers of the Mexican experience have long noticed the intermingling of nature and humanity at critical junctions in the region's past. The island city of Tenochtitlan enthralled Bernal Díaz who described the floating gardens and intricate causeways that meandered through the lacustrine setting. On the eve of independence, Alexander von Humboldt heaped praise on the wealth of extant natural resources, especially the mines of Guanajuato and the vanilla in Veracruz. In the later nineteenth century in Chiapas and the Yucatán, ancient Mayan temples were identified under such dense vegetation that they had to be “unearthed,” and such excavations led to recurrent (and overly rigid) explanations for the collapse of the Maya civilization marking the decline as a parable of environmental catastrophe. Even the famed United States conservationist, Aldo Leopold, remarked on the integrity of Chihuahua's high montane ecosystems that supported large predators, including wolves and bears, in the 1940s. Observers of the Mexican environment repeatedly found themselves overwhelmed by the nature they encountered and their remarks remind us of the constraints the natural world places on humanity. Yet descriptions of natural attributes alone hardly constitute environmental history. Rather than an austere catalog of waterways or plant species, environmental history poses social and cultural questions and is distinct from its predecessor, natural history. An environmental approach to history adds a consideration of the power that resides outside human control and interrogates the interactions between social and natural systems over the long term. Such an approach to the past allows recognition of how humanity depends on and relates to natural systems. In doing so, environmental history helps account for contingencies that remain beyond the scope of traditional histories. This chapter points to some fruitful arenas for understanding the relationships among the realms of political, economic, social, and cultural history and the natural world that hosts these contestations.